gistfile1.txt

#! /usr/bin/env python
# -*- coding: utf-8 -*-

import sqlalchemy
from sqlalchemy.ext.declarative import declarative_base

engine = sqlalchemy.create_engine('postgresql://osm:@/osm')

Base = declarative_base()

class Coord_Way(Base):
  __tablename__ = 'coord_way'
  coord_osmid = sqlalchemy.Column(sqlalchemy.BigInteger, sqlalchemy.ForeignKey('coord.osmid'), primary_key=True)
  way_osmid = sqlalchemy.Column(sqlalchemy.BigInteger, sqlalchemy.ForeignKey('way.osmid'), primary_key=True)
  index = sqlalchemy.Column(sqlalchemy.Integer, primary_key=True)

  way = sqlalchemy.orm.relationship('Way', back_populates='coords')
  coord = sqlalchemy.orm.relationship('Coord', back_populates='ways')

class Coord(Base):
  __tablename__ = 'coord'

  osmid = sqlalchemy.Column(sqlalchemy.BigInteger, primary_key=True)
  lon = sqlalchemy.Column(sqlalchemy.Float)
  lat = sqlalchemy.Column(sqlalchemy.Float)

  ways = sqlalchemy.orm.relationship('Coord_Way', back_populates='coord')

class Way(Base):
  __tablename__ = 'way'
  
  osmid = sqlalchemy.Column(sqlalchemy.BigInteger, primary_key=True)

  coords = sqlalchemy.orm.relationship('Coord_Way', back_populates='way')

#Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
Session = sqlalchemy.orm.sessionmaker(bind=engine)

gistfile2.txt

osm=> \d coord_way
                             Table "public.coord_way"
   Column    |  Type   |                         Modifiers                         
-------------+---------+-----------------------------------------------------------
 coord_osmid | bigint  | not null
 way_osmid   | bigint  | not null
 index       | integer | not null default nextval('coord_way_index_seq'::regclass)
Indexes:
    "coord_way_pkey" PRIMARY KEY, btree (coord_osmid, way_osmid, index)
Foreign-key constraints:
    "coord_way_coord_osmid_fkey" FOREIGN KEY (coord_osmid) REFERENCES coord(osmid)
    "coord_way_way_osmid_fkey" FOREIGN KEY (way_osmid) REFERENCES way(osmid)

osm=> \d coord    
                               Table "public.coord"
 Column |       Type       |                       Modifiers                       
--------+------------------+-------------------------------------------------------
 osmid  | bigint           | not null default nextval('coord_osmid_seq'::regclass)
 lon    | double precision | 
 lat    | double precision | 
Indexes:
    "coord_pkey" PRIMARY KEY, btree (osmid)
Referenced by:
    TABLE "coord_way" CONSTRAINT "coord_way_coord_osmid_fkey" FOREIGN KEY (coord_osmid) REFERENCES coord(osmid)

gistfile3.txt

osm=> select coord.lat, coord.lon from coord_way join coord on coord.osmid = coord_way.coord_osmid where coord_way.way_osmid = 384003068 order by coord_way.index;
       lat        |    lon     
------------------+------------
 52.0003068000003 | 13.5857798
 52.0003264000001 | 13.5859906
 52.0010553000001 | 13.5915687
       52.0037425 | 13.5907274
 52.0043408000001 | 13.5904935
(5 rows)